Disk drives are widely used in computers and data processing systems for storing information in digital form. In conventional disk drives, a transducer “flies” upon an air bearing in very close proximity to a storage surface of a rotating data storage disk. The storage surface carries a thin film of magnetic material having a multiplicity of magnetic storage domains that may be recorded and read back by the transducer.
As computer use continues to increase, there is naturally a corresponding increase in the need to find sufficient data storage space for the data on the computer. Presently, storage systems are used to backup data from computer systems. One type of storage system utilizes one or more tape drives and one or more tape cartridges. Tape storage systems are relatively inexpensive to operate and can store relatively large amounts of data. However, tape backup systems provide relatively slow access to the data.
Another type of storage system utilizes a plurality of disk drives that are positioned within a housing. Disk storage systems provide relatively quick access to data. Unfortunately, the disk drives can generate significant amounts of heat energy during normal operation. This heat energy must be removed from the housing to inhibit the disk drives from reaching or exceeding the maximum operating temperature, which may cause one or more of the disk drives to fail prematurely.
A typical cooling system relies upon moving large volumes of air across the disk drives to remove the heat energy. This type of cooling system requires relatively large open spaces around the disk drives. The necessity of these open spaces limits the overall density of the disk drives relative to the volumetric space of the storage system.
When used for primary storage, there is also a strong motivation to have each individual disk drive be easily accessible for the purposes of replacing failed drives without having to power down the entire unit or affect the operation of other non-failed drives. This also places limitations on how densely disk drives may be packaged in a disk array. If the disk array is used for infrequently accessed data, such as would be the case for a secondary storage array, an array used for backup purposes, or an array emulating a tape drive system, the requirements for physical accessibility of individual drives can be greatly relaxed allow much greater packing densities. Furthermore, short periods of inaccessibility or delays in access are generally tolerable in these types of applications.
In light of the above, there is a need for a storage system having a relatively large data storage capacity and a relatively small system footprint. Additionally, there is a need for a storage system that reduces the amount of heat generated by the storage system. Further, there is a need for a storage system having enhanced reliability and durability.